Depression is a mental disorder that makes an individual responsive to negative stimuli as higher cognitive functions of the brain of the individual like perception, attention, memory related functions, planning, decision making etc. are seriously challenged by the causes like excessive stresses in life, serious illness, loss of self-esteem, certain medications etc. Erroneous information processing in the brain of depressive individuals attaches them to the feelings of loss, sadness and hopelessness. In extremely stressful situation the cognitive functions of the depressive individuals may be impaired to such an extent that they may have the feeling of entrapment for which they can take the way of suicidal acts for escape. A number of brain regions that are involved in higher cognitive functions are altered in depression patients, suicidal individuals and in complete suicides. Along with the morphological changes, monoaminergic neurotransmission system is also severely deteriorated in these brain regions indicating their possible involvements in regulating cognitive activities. Monoaminergic dysfunctions may give rise to serious cognitive impairments and deterioration of associated mental functions required for maintaining normal internal homeostasis. Loss of cognitive functions makes an individual incapable to interact properly to various aspects of normal life functions making them depressive and severe depression may be the forerunner of suicidal acts.